The present invention relates to a feeder head assembly used in conjunction with an unloading apparatus to transfer bulk materials, particularly pulverized or comminuted materials, from relatively large cargo containers or vessels to a material transport, handling or storage system. More particularly, this invention relates to a feeder head assembly used in conjunction with an unloading apparatus to transfer dry cement or other bulk, powdered material from cargo containers or vessels to a material transport, handling or storage system.
The transfer of various comminuted materials presents difficult problems. However, Portland cement, because of its physical properties, is particularly troublesome. Dry cement is a fine powdered material, 100 mesh or smaller in size. When moved and handled in bulk form, it presents dust problems. It is mildly abrasive, and it flows relatively freely at an angle of repose of 35.degree. to 40.degree.. When aerated it becomes fluid-like, but when packed or settled it becomes dense and difficult to handle. Large masses of cement present additional handling problems. Upon removal of a portion of a large mass of cement beyond the angle of repose of the remaining mass, the remaining mass shifts, changing its surface configuration.
The equipment used to unload the cement must first engage the cement, collect it and then move it out of the cargo container or vessel while controlling the dust. The collecting and feeding apparatus must have a certain degree of flexibility. It must adjust to the configuration of a mass of cement so that it may engage the cement and advance into the sloping sides of the mass. In addition, it must adjust to the configuration of the floor and walls of the vessel that it unloads.
Although increased flexibility provides desirable advantages, it usually results in increased complexity of the equipment. Such unloading equipment also tends to be large and heavy, and thus it is capable of causing damage to itself, the vessel and surrounding structures. However, the unloading equipment must be simple and easy to operate. In addition, it should preferably be self adjusting. Furthermore, it should minimize the risk of damage from improper and careless operation. Finally, the apparatus should be durable to resist the abrasive properties of the cement.
The feeder head assembly of the present invention used in conjunction with a mobile unloading apparatus fulfills the above requirements. It is simple, flexible, durable and mobile. It allows the unloading apparatus to engage the cement and to smoothly, cleanly and efficiently remove it from any location in the cargo container or vessel. Moreover, it includes features which minimize the risk of damage from improper or careless operation.